Sewing machine loop-taker



p 1943- D. A. GRAESSER 2,33,35

SEWING MACHINE LooP-T'AxER Filed March 11 1942 David O. graeddez Wii'we66 Patented Sept. 28, 1943 SEWING MACHINE LOOP-TAKER David A. Graesser, Westfield, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application March 11, 1942, Serial No. 434,214

' (Cl. 1'12 22s) 11 Claims.

This inventionrelates to sewing machine looptakers and is particularly applicable to rotary loop-takers having a cup-shaped body in which is journaled a thread-carrier restrained against rotation with the loop-taker.

The object of this invention is to obviate accumulation to a detrimental degree of lint and sheet-material filling matter upon the inner face of the cylindrical side wall of a sewing machine loop-taker and, more particularly, inwardly of the bearing support of the thread-carrier which is journaled in the loop-taker.

The invention consists in the provision of means, effective during the operation of a sewing machine, for Wiping the inner side face of a sewing machine loop-taker without interference with stitch formation, as hereinafter described in connection with the accompanying drawings, which illustrate a preferred embodiment of the invention and in which:

Fig. 1 is an enlarged rear side elevation of the thread-carrier of a sewing machine loop-taker provided with the present improvement. Fig. 2 is an enlarged cross section of a sewing machine loop-taker and its thread-carrier, the section being taken substantially medianly across the novel 1 wiper device. Fig. 3 is an enlarged cross section of fragments of the associated loop-taker and thread-carrier, the section being takenlengthwise of the wiper device. Fig. 4 is an enlarged front side elevation of the loop-taker and thread-carrier, in the position of the loop-taker in which the cast off needle-thread loop is being drawn onto the tail of the loop-taker, proximate parts of the sewing machine being shown partly in vertical section and partly in front elevation.

As illustrated in the drawing, the present improvement has been embodied in a horizontalaxis rotary loop-taker constructed substantially as disclosed. in the U. S. patents of C. A. Kessler, No. 1,995,278, March 19, 1935 and No. 2,085,699, June 29, 1937.

Referring to the drawing. the loop-taker has a generally cup-shaped body member. including a cylindrical side wall I and a hub 3 adapted to be secured by screws 4 upon a horizontally disposed rotary actuating shaft (not shown). The cylindrical sidewall I of the looptaker is partly cut away to provide at its outer edge a needle-thread loop seizing beak 5. .The loop-seizing beak 5 is opposed to and spaced sli htly from a loop-discharging tall or spur '6 provided upon a segmental gib I having an inwardly directed or radial side flange 8; said gib "I an end wall 2 having being detachably secured by screws 9 upon the cylindrical side wall I of the loop-taker.

Removably secured by screws I I] upon and overlying a portion of the cylindrical side wall I of the loop-taker is a segmentalsheet-metal plate II. The tapered advance portion I I' of the segmental plate II extends partly across the'gap between the beak 5 and the tail 6 of the looptaker; said tapered portion II of the plate being as usual complemental to the beak 5 in directing the limbs of the needle-thread loop. The side wall I of the loop-taker is cut away circumferentially to provide an internal raceway I2 which is in part completed by the side flange 8 of the removable gib 1.

Journaled in the raceway I2 and thereby having a bearing support in the loop-takeris a peripheral and circumferentially extending bearing-rib I3 of a thread-carrier member I4; said member I4 having a generally cylindrical side wall I5 at opposite sides of the bearing-rib I3 and also having an axial thread-case supporting post I6. The bearing-rib I3 is interrupted to provide the usual needle-thread clearance gap between a thread-loop arresting shoulder I! and its opposed loop-discharge shoulder I8 of the bearing-rib. Supported by the post I I3 is the usual thread-case I9 containing the interlocking or bobbin-thread B about which loops of needlethread N are cast by the loop-taker in the formation of lock-stitches. The rim of the threadcarrier member I4 is formed with an outer segmental flange .Zil'having the upper portion thereof provided with a stop-notch 2i adapted loosely to receive a stop-lug 22 of a stationary stopfinger 23, thereby to restrain the thread-carrier against rotation with the loop-taker. 1 The cylindrical side wall I5 of the thread-carrier member I 4 is preferably disposed in close proximity to the inner face of the loop-taker side wall I, so that said member I4 may have a maxi- 'mum capacity for interlocking thread. However, as it is necessary to pass the needle-thread N between said walls I and I5, it is detrimental to stitch formation to permit clogging of the space between said walls I and I5 by an accumulation of lint and filling matter dislodged from sheet materials being stitched. Furthermore, the adherence of foreign matter to the inner face of theloop-taker tends to lower dissipation of heat which is frictionally created by the relatively rotating parts.

.The loop-taker described is located below the usual work-supporting bed-plate 24 of a sewing machine provided with a suitably slotted and apertured throat-plate 25. Operating through the throat-plate 25 is a feed-dog 28 which is yieldingly opposed, in its upward movement and above the work-support, by a presser-foot 21; said feed-dog functioning to advance the work W intermittently past the vertically reciprocatory thread-carrying needle 28.

In accordance with the present invention, the portion of the cylindrical wall l5 extending inwardly of the loop-taker from the bearing-rib 13 of the thread-carrier member is cut away in its outer face to provide a segmental recess 29. This recess is preferably located in that circumferential portion of the thread-carrier wall I5 corresponding to the third quadrant of rotation of the loop-taker beak 5 after seizure of a needle thread loop. In other words, the recess '29 is preferably located in the zone of rotation of the loop-taker beak wherein the needle-thread loop N is drawn on from the beak 5 and onto the tail 5 of the loop-taker, during the formation of stitches.

Disposed in said recess 25! and lengthwise extending circumferentially of the thread-carrier member 14 is a wiper element 3.0 of leather or other suitable material. The wiper element 30 is bowed outwardly between its ends and, preferably, barely to contact the inner or proximate face of the side wall I of the loop-taker; the opposite ends of said wiper element30 being suitably secured, as by'rivets 3!, to the side wall of the thread-carrier member in the recess 29 thereof. The wiper element 39 widthwise preferably extends across substantially the entire outer face of the thread-carrier member side wall portion l5 which is disposed inwardly of the bear- Being bowed outwardly between its ends, the wiper element 38 has resiliently yielding characteristics insuring efiicient wiping action without giving rise to undue friction. It is to be understood, however, that the wiper device may be constructed and secured otherwise than as above described, within the spirit of'the present invention.

In the operation of the sewing machine, the loop-taker beak 5 seizes a loop of thread N, presented by the needle 28, .and expands said loop in casting it about the thread-carrier member l4 in the usual manner. As described in detail in the Kessler Patent No. 1,995,278, hereinbefore mentioned, the limb of the loop of needle-thread N which is arrested by the bearing-rib shoulder 11 and which extends to the needle is cast inwardly upon the end wall face of the threadcarrier member I'! within approximately 150 of rotation of the loop-taker beak 5 after seizure of the needle-thread loop. Prior to being cast upon the end wall of the thread-carrier member, the limb of the thread-loop arrested by the shoulder I1 is wrapped in a generally circumferential direction about the outer face of the side wall i5 of the member i l inwardly of the bearing-rib 33. Consequently, clogging of the thread clearance space between the side wall I 5. of the threadcarrier member and the side wall 'I .of the looptaker tends to interfere with proper expansion of the needle-thread loop.

Likewise, after the loop of needle-thread has been drawn off from the beak 5 of the loop-taker and onto the tail thereof, as illustrated in Fig. 4 of the drawing, the inner limb of said loop is again drawn over the inner edge of the threadcarrier member Hi and upon the outer face of the side wall l5 of said member, thereby requiring thread clearance space between the wall l ing-rib i3.

of the loop-taker and the wall l5 of the threadcarrier member.

In the preferred embodiment of the present invention, the wiper device is located between the points at which the thread-loop is cast off the inner edge of the thread-carrier member and again drawn upon the outer face 15 of said member. As hereinbefore described, the preferred location of the wiper device is in the zone corresponding to the third quadrant of rotation of the loop-taker beak 5 wherein the needlethread loop is drawn off from said beak and is caught by the tail 6, as in that location the likelihood of interference with stitch formation by the wiper device is obviated.

Having thus set forth the nature of the invention what I claim herein is:

-1. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall provided with a needle-thread-loop seizing beak, a thread-carrier member having a bearing support in said body-member, said thread-carrier member having a generally cylindrical side wall disposed within and spaced from said side wall of the loop-taker body-member at one side of said bearing support, and a wiper-element carried by and extending from the outer face of said thread-carrier member into wiping relation with the inner face of said side Wall of the loop-taker body-member.

2. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall provided with a needle-thread-loop seizing beak, a thread-carrier member having a bearing support in said body-member, said threadcarrier member having a generally cylindrical side wall disposed within and spaced from said side wall of the loop-taker body-member at one side of said bearing support, and a resilient wiper device carried by and extending from the outer face of, said thread-carrier member into wiping relation with the inner face of said side wall of the loop-taker body-member.

3. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall-provided with aneedle-thread-loop seizing beak, a thread-carrier member having a bearing support in said bodymember, said threadcarrier member having a generally cylindrical side wall portion extending inwardly of said looptaker body-member from said bearing support in spaced relation to said side wall of the loop-taker body-member, and wiper means disposed between said side wall portion of the thread-carrier member and said side wall of the loop-taker.

l. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall provided with a needle-thread-loop seizing beak, a thread-carrier member having a bearing support in said body-member, said thread-carrier member having a generally cylindrical side wall portion extending inwardly of said loop-taker body-member from said bearing support in spaced relation to said side wall of the loop-taker bodymember, and a wiper device extending from said side wall portion of the thread-carrier member into wiping relation with the proximate inner face of said side wall of the loop-taker bodymember.

5. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall provided with a needle-thread-loop seizing beak, a thread-carrier member having a hearing support in said body-member, said threadcarrier member having a generally cylindrical resilient wiper-element bowed between its ends away from one of said walls toward the proximate face of the other of said walls;

6. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall provided with a needle-thread-loop seizing beak, a thread-carrier member having a bearing support in said body-member, said thread-carrier member having a generally cylindrical side-wall portion extending inwardly of said loop-taker body-member from said bearing support in spaced relation to said side wall of the loop-taker body-member, and a wiper-element carried by and lengthwise extending circumferentially of said thread-carrier member wall portion, said wiper-element being bowed outwardly between its ends toward the inner face of said side wall of the loop-taker body-member.

7. A rotary loop-taker for sewing machines, including a body-member having a cylindrical side wall provided with a needle thread-loop seizing beak, a thread-carrier member journaled in said body-member and having a generally cylindrical side wall disposed within and spaced from said side wall of the loop-taker body-member, said side wall of the thread-carrier member being providedin its outer face with a circumferentially elongated recess; and a wiper-element secured in said recess and disposed in wiping relation with the inner face of said side wall of the loop-taker body-member.

8. In-a sewing machine having a threadcarrying needle, a rotary loop-taker having a cylindrical side wall provided with a needle-threadloop seizing beak, a thread-carrier member having a generally cylindrical side wall journaled in and spaced from said wall of the loop-taker, and means for restraining said thread-carrier member against rotation with said loop-taker, the improvement which consists in the provision between said walls of means for wiping the inner face of said side wall of the loop taker, said means comprising a wiper-element carried by said side wall of the thread-carrier member in the zone thereof corresponding to the third quadrant of rotation of said beak of the loop-taker after seizure of a needle-thread loop presented by said needle. 7

9. In a sewing machine having a thread-carrying needle, a rotary loop-taker including a body-member having a cylindrical side wall provided with a needle-thread-loop seizing beak and a thread-carrier member having a bearing support in said body-member, said thread-carrier member having a generally cylindrical side wall portion extending inwardly of said loop-taker body-member from said bearing support in spaced relation to said side wall of the loop-taker bodymember, and means for restraining said'threadcarrier member against rotation with said looptaker, the improvement which consists in the provision of wiper means carried by said threadcarrier member wall portionin the circumferential zone thereof corresponding substantially to the position of said loop-taker beak inwhich the needle-thread-loop is drawn oii from said beak, said wiper means extending from the outer face of said wall of the thread-carrier member toward the proximate face of said side wall of the looptaker body-member.

10. A thread-carrier member for sewing machine loop-takers, comprising, a body having a generally cylindrical side wall provided circumferentially thereof with an interrupted bearingrib, and a wiper-element carried by and extending yieldingly outwardly from the outer face of said side wall adjacent said bearing-rib.

11. A thread-carrier member for sewing machine loop-takers, comprising, a body having a generally cylindrical side wall provided circumferentially thereof with an interrupted bearingrib, said side wall being provided in its outer face adjacent said bearing-rib with a recess, and a wiper-element lengthwise extending circumferentially of said side wall and secured in said recess, said wiper-element being yieldingly bowed outwardly between its ends.

DAVID A. GRAESSER. 

